For cellular mobile radio networks like GERAN, UTRAN, LTE/E-UTRAN, LTE-Advanced, cdma2000, WiMAX, WiBro, etc., broadcast capabilities have been designed which range from SMS cell broadcast (SMS-CB), invented for GSM where the service allows the delivery of short, mainly text based limited length messages, over MBMS (Multimedia Broadcast and Multicast Service) or IMB (Integrated Multimedia Broadcast) for UTRAN in 3GPP Rel-6 and enhanced Multimedia Broadcast and Multicast Service (eMBMS) for LTE/E-UTRAN in 3GPP Rel-9 or later. Later technologies allow distribution of multimedia content, and also text or graphic services in a broadcast fashion. Also, there are non-cellular mobile technologies to deliver multimedia content (e.g. MobileTV), namely DVB-T/-H/-S, MediaFLO, DMB, etc. Another area gaining interest for the delivery of broadcast messages is the request of authorities to enable a warning system for the public (mobile cellphone users) in case of emergency—in this area, different approaches exist due to differing requirements from different local authorities. Prominent examples of such technologies defined by 3GPP for mobile users are ETWS (Earthquake and Tsunami Warning System) mainly used in Asian markets, PWS/CMAS (Public Warning System/Commercial Mobile Alert System) mainly used in North America, and SMS-CB (currently under discussion in Europe).
Conventional approaches have a common principle: that a message is delivered to all or a selected number of terminal devices in a PLMN or subpart of a PLMN. The minimum geographical area where messages can be delivered is a single cell for cellular mobile communications networks. In more general terms (including also the case of non-cellular transmission modes of mobile communication networks), the minimum geographical area where messages can be delivered is a local radio coverage area typically served by a radio access network entity like a base transceiver station or another device having a radio antenna for broadcast purposes. Typically, a cellular network includes a multitude of radio cells. A radio cell is the geographic area of the cellular mobile network in which the radio signal transmitted by a base station can be received. In most of the cellular technologies the range of a macro base station is in the order of 500 meters to 1000 meters in urban areas while typically in rural areas cells have a radius of 5 kilometers to 10 kilometers and even higher up to 135 kilometers in UMTS for specific frequency bands. In non-cellular radio technologies the coverage area of a single base station is normally much larger, e.g. 50 kilometers to 100 kilometers in DVB-T and several hundred kilometers when using satellite broadcasting technologies like DVB-S.
This means that with conventional technologies, a cell broadcast event or a broadcast action within the local radio coverage area (of a radio access network entity) means that many mobile terminals might be involved even in such cases where only a specific geographical part or subarea of the local radio coverage area are concerned or should be concerned by the cell broadcast (or local radio coverage area broadcast) event. With current wireless technologies, the minimum geographical delivery area of broadcast messages corresponds to the area of a cell (or local radio coverage area).